Can lumbar decompression surgery make sacroiliac joint pain worse?

Doctors in Germany examined a potential connection between lumbar decompressive surgery and new onset of sacroiliac joint-related pain causing a diagnosis of “failed-back-surgery.”

Here is what they said in their newly published research:
Patients with lumbar stenosis do have substantially positive results from decompressive surgery. HOWEVER the change of body position and walking behaviour after successful surgery might lead to changed force effects on the entire spine and on the sacroiliac joint (SIJ).

The authors analyzed the records of 100 consecutive patients from three institutions, who underwent decompressive surgery without instrumentation. The diagnosis of SIJ-related pain was confirmed by periarticular infiltration. The radiological changes of the sacroiliac joint were assessed in plain radiographs in both groups: patients with SIJ pain (group 1) and patients without SIJ pain (group 2)